DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1
A bstract Pinnipeds forage almost exclusively underwater. Consequently, observing them is difficult and relatively little is known of how they use their senses to locate prey, avoid predators, and navigate while diving. Vision has been presumed to be of primary importance, although previous measurem...
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crwiley:10.1111/j.1748-7692.1999.tb00892.x 2024-09-30T14:34:21+00:00 DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1 Levenson, David H. Schusterman, Ronald J. 1999 http://dx.doi.org/10.1111/j.1748-7692.1999.tb00892.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.1999.tb00892.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.1999.tb00892.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 15, issue 4, page 1303-1313 ISSN 0824-0469 1748-7692 journal-article 1999 crwiley https://doi.org/10.1111/j.1748-7692.1999.tb00892.x 2024-09-19T04:18:38Z A bstract Pinnipeds forage almost exclusively underwater. Consequently, observing them is difficult and relatively little is known of how they use their senses to locate prey, avoid predators, and navigate while diving. Vision has been presumed to be of primary importance, although previous measurements of visual functioning in pinnipeds have been restricted to just a few shallow‐diving species. As diving pinnipeds experience rapid changes in light levels during descent/ascent and low light levels at depth, it has not been clear whether they possess visual capabilities adequate for use while diving, particularly in the case of deep‐diving species. To examine this issue, behavioral psychophysics have been used to assess and compare the dark adaptation rates and relative light sensitivities of a deep‐diving pinniped (northern elephant seal, Mirounga angustirostris ), two shallow‐diving species (California sea lion, Zalophus californianus , and harbor seal, Phoca vitulina ), and a human subject. In comparison to the human subject, both the California sea lion and the harbor seal dark‐adapted relatively quickly and were more light sensitive. These findings suggest that both of these species are well suited for vision in the moderately dim shallow‐water environments in which they dive to forage. In contrast, the elephant seal reached complete dark adaptation in less than half the time taken by the other pinnipeds, and it was significantly more light sensitive. Unlike the shallower‐diving species, the visual abilities of the elephant seal are commensurate with the extreme conditions experienced while deep diving. Thus, we conclude that elephant seals are sufficiently adapted to rely on vision underwater, even while diving to depths in excess of 1000 meters where bioluminescence may be the sole source of ambient light. Article in Journal/Newspaper Elephant Seal Elephant Seals harbor seal Phoca vitulina Wiley Online Library Marine Mammal Science 15 4 1303 1313 |
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Wiley Online Library |
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English |
description |
A bstract Pinnipeds forage almost exclusively underwater. Consequently, observing them is difficult and relatively little is known of how they use their senses to locate prey, avoid predators, and navigate while diving. Vision has been presumed to be of primary importance, although previous measurements of visual functioning in pinnipeds have been restricted to just a few shallow‐diving species. As diving pinnipeds experience rapid changes in light levels during descent/ascent and low light levels at depth, it has not been clear whether they possess visual capabilities adequate for use while diving, particularly in the case of deep‐diving species. To examine this issue, behavioral psychophysics have been used to assess and compare the dark adaptation rates and relative light sensitivities of a deep‐diving pinniped (northern elephant seal, Mirounga angustirostris ), two shallow‐diving species (California sea lion, Zalophus californianus , and harbor seal, Phoca vitulina ), and a human subject. In comparison to the human subject, both the California sea lion and the harbor seal dark‐adapted relatively quickly and were more light sensitive. These findings suggest that both of these species are well suited for vision in the moderately dim shallow‐water environments in which they dive to forage. In contrast, the elephant seal reached complete dark adaptation in less than half the time taken by the other pinnipeds, and it was significantly more light sensitive. Unlike the shallower‐diving species, the visual abilities of the elephant seal are commensurate with the extreme conditions experienced while deep diving. Thus, we conclude that elephant seals are sufficiently adapted to rely on vision underwater, even while diving to depths in excess of 1000 meters where bioluminescence may be the sole source of ambient light. |
format |
Article in Journal/Newspaper |
author |
Levenson, David H. Schusterman, Ronald J. |
spellingShingle |
Levenson, David H. Schusterman, Ronald J. DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1 |
author_facet |
Levenson, David H. Schusterman, Ronald J. |
author_sort |
Levenson, David H. |
title |
DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1 |
title_short |
DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1 |
title_full |
DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1 |
title_fullStr |
DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1 |
title_full_unstemmed |
DARK ADAPTATION AND VISUAL SENSITIVITY IN SHALLOW AND DEEP‐DIVING PINNIPEDS 1 |
title_sort |
dark adaptation and visual sensitivity in shallow and deep‐diving pinnipeds 1 |
publisher |
Wiley |
publishDate |
1999 |
url |
http://dx.doi.org/10.1111/j.1748-7692.1999.tb00892.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.1999.tb00892.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.1999.tb00892.x |
genre |
Elephant Seal Elephant Seals harbor seal Phoca vitulina |
genre_facet |
Elephant Seal Elephant Seals harbor seal Phoca vitulina |
op_source |
Marine Mammal Science volume 15, issue 4, page 1303-1313 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1748-7692.1999.tb00892.x |
container_title |
Marine Mammal Science |
container_volume |
15 |
container_issue |
4 |
container_start_page |
1303 |
op_container_end_page |
1313 |
_version_ |
1811637995468488704 |